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  1. #41
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    My Z axis

    In the picture some material for my Z axis
    Any good idea for the best way to build Z axis control ( lead screw ) ?
    Paolo

  2. #42
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    ..and My Attachement..

    ..and my attachement ( picture ) is lost in cyberspace.......
    Paolo

  3. #43
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    Xmas

    To all the DIY CNC machinists
    Merry Christmas
    and a very successfull
    new year


    by ciccio

  4. #44
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    low cost smt pick and place , printer conversion

    Hi to all,
    i have made the conversion of a lexmark 3200 printer to a small pick and place
    system.
    I was able to utilize the cleaning part inside the printer as Z-rail with a
    travel of appozimate tree cm. This rail and the C axis is piloted using a common rc mini-servo.
    External parts used and costs:
    lexmark printer, 0 Euro, received from a friend
    tree way solenoid: 30 Euro
    two smd pick-up pen including vacuum pump: 70 Euro
    small fan: 4 Euro
    pcb bottle for concentrating the air flow produced from the fan: 0 Euro.
    silicone tube for vacuum pen, 0.2 Euro
    rc-servos, 2x 15 Euro = 30 Euro ( i know, this can be sourced for 5 Euro/pc)
    electronic (pic,..., stepper motor controller used from the printer board) 10 Euro.
    USB optical mouse, 12 Euro, used as high speed, low cost vision system.
    linear guides as used for drawers, 12 Euro
    two wood plates, some wood spacers and rubber foam, 5 Euro.
    The hw is in place, for the electronic i need to make a pcb, currently it´s
    wire wrap and on experimenter boards.

  5. #45
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    Apr 2003
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    34

    Please Post Pictures

    Quote Originally Posted by nisma View Post
    Hi to all,
    i have made the conversion of a lexmark 3200 printer to a small pick and place
    system.
    I was able to utilize the cleaning part inside the printer as Z-rail with a
    travel of appozimate tree cm. This rail and the C axis is piloted using a common rc mini-servo.
    External parts used and costs:
    lexmark printer, 0 Euro, received from a friend
    tree way solenoid: 30 Euro
    two smd pick-up pen including vacuum pump: 70 Euro
    small fan: 4 Euro
    pcb bottle for concentrating the air flow produced from the fan: 0 Euro.
    silicone tube for vacuum pen, 0.2 Euro
    rc-servos, 2x 15 Euro = 30 Euro ( i know, this can be sourced for 5 Euro/pc)
    electronic (pic,..., stepper motor controller used from the printer board) 10 Euro.
    USB optical mouse, 12 Euro, used as high speed, low cost vision system.
    linear guides as used for drawers, 12 Euro
    two wood plates, some wood spacers and rubber foam, 5 Euro.
    The hw is in place, for the electronic i need to make a pcb, currently it´s
    wire wrap and on experimenter boards.
    Sound's way cool!!!!
    Could you post some pictures?

  6. #46
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    I am interested in hearing more about the optical mouse as a vision system. Are you using the mouse to detect if a part is even on the nozzle? How much rotation you need on the nozzle to align the part correctly? or some other reason. Yes, please post pictures

  7. #47
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    pick & place

    Hi nisma:
    congratulations ! You did it!
    A lot of interesting solutions !
    We need more infos and a lot of pictures.
    ...and that damned optical mouse :
    that is really art .
    Paolo

  8. #48
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    pick & place

    ...sorry, nisma, I forgot :
    what about result / precision ?
    What about feeders ?
    What about speed ( not so important in this beta stage )
    very very interested !
    PS are you italian ? I live near Cuneo.
    Saluti
    Paolo

  9. #49
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    The mouse sensor gives from 64x64 pixel output to 160x200 pixel for some
    sensors at high speed, from 200HZ up to 2.5 KHZ.
    Search for "hacking optical mouse". I use it for aligning the pcb and the
    placement coordinates and do detect the components to pick including the
    displacement.
    For the feeders, i have a solution, even it´s needs four cm every reel, because i use RC servos.
    I have some modifications in mind and xxx.
    The precision is 4 mil without microstepping, and the speed is 1.5 second/component for the planned design modification.
    The planned changes is to make two sliders, one for the pcb and annother for
    the components, in order to optimize the pcb sliding and to improvere the
    efficience. Additional this allows preparing the components (reels strips,...)
    on a panel and loading in on the pcb tray. Then the pick and place machine
    moves the component from the pcb tray to the components tray.
    The overall speed including loading the components will be between 5 and 10
    seconds. For real production systems, it´s supposable to use one printer
    for loading the parts from reels/feeders and annother for pick and place parts
    and interconnects this two printers using a small turn table, concretly a cd mounted on a rc servo.
    Then one or more pcb´s can be assembled using the components stored on
    the components rail. Additionally four reels feeders are planned for generally
    used resistors, like 10k, and so on. It´s possible to modify one use and trash
    35mm film camera to handle the reel transport system. Ask photo developing
    shops to get some from it for free instead of trashing it after removing the
    film. The drawback of this system is, that it needs
    4 cm every feeder, so only four reel feeders are planned.
    Some have a flash inside it. You can use it as error signals, like the industrial
    control signals if something need user intervention.

    Someone has one idea about needle tooling and changing ?

    I can make photos only in then days, because i receive back my digital camera from my sister after she returns from asia trip.
    Sorry for the longer delay.

  10. #50
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    ...curiosity....

    Hi Nisma,
    ....so let me see:
    4 mil WITHOUT microstepping
    2.400 components/hour ( 1,5 sec/comp)
    It seems to me there is a lot of work and developement in this machine.
    Waiting for pictures !
    About nozzles : have you seen:
    http://cgi.ebay.com/Assembleon-FCM-n...QQcmdZViewItem
    I can send you a nozzle PA 2747/20 Philips-Assembleon ( 0603-1206-sot23), I think nothing is better than a professional nozzle, especially if I can buy it at an inexpensive price on ebay.
    It seems to me you used "off the shelf" components: an old printer, rc servos, and so on: this means ,with a little help, now we can start thinking to build our pick and place .
    Thanks, Nisma, and please do not forget the pictures; we are counting the days !
    Paolo

  11. #51
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    I have the nozzles, but i need a system, that lets the machine change
    the nozzles (tooling) without operator intervention.
    The 2.4000 components it´s only true for placement from the reel,
    otherwise 1.200 components/hour is realistic.

  12. #52
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    Tooling

    I think the form of a nozzle allows to put and take it from some sort of wide-toothed comb. Can someone help us with a picture from a P&P ?
    I also think this needs some work for milling machines.
    Some question again:
    do you modify rc-servos?
    For example on the theta (rotation) axis ? A servo only rotates about +- 130 degrees. It needs to rotate endless on the feeder.
    Do you use some sort of "spring" on Z axis to compensate different high ( feeder-PCB)?
    Please tell us more !
    Paolo

  13. #53
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    I have seen some photos from a P&P machine, but i need a cheap idea,
    how to hold and separate the needle adapter.
    The nozzle proposed from ciccio don´t work, because the printer need
    more height clearance and this nozzles are basically designed for
    using it with solenoids, but this are too heavy as to be used on low cost printers without modifying the linear sliding rails on the printers.
    If someone has a dot-matrix printer, then it will maybe work, but today,
    this are either too costly or not easy to find for dismissed parts.
    This type of nozzles can be used on a x/y/z table with several nozzles and
    it will works really nice, no nozzle tooling is required, because several (different) nozzles can be used in parallel. Further this type of P&P eqipment is really fast, because the increased count of nozzles automatically multiply the placement capacity. It´s obvious, that this is a totally different design and costs at least 10 times more then utilizing a printer. My approach is to use low cost
    cots components as mutch as possible and eventually using multiple machines
    in order to increase the troughtput.
    To respond to the questions,
    for the Z axis, i have used the cleaning assemble from the lexmark printer.
    This has a spring inside and i have replaced the two internal springs with
    the springs from the paper feeder in order to eliminate the backlash when
    moving the Z axis. The axis is moved with a rc-servo and the cleaning
    assemble convert the rotational movement of the servo to a linear movement
    of 3cm maximal travel. The height differences including the height clearance for the components on the pbc should be in the range of 3cm in order that
    the pcb can be assembled with the machine.
    It´s possible to extend the travel to 5cm, but this needs some work with a real cnc machine.
    The C rotation (theta) currently uses unmodifyed servos.
    For now, this is sufficient. Later, the servo can be replaced with a modificated one, when this is needed or desired.
    For the rc-servos on the feeders, i have removed the electronic and power the servo with 2V (3V on the negative pole, 5V on the positive).
    For now, the feeder motor is activated for a certain amount of time, and
    then it stops. When the head picks up the component, the optical sensor
    measures the position and rotation including the advancing error.
    This works pretty well. It´s possible to add optical or mechanical sensors
    for measuring the advancing of the reel (1-3$), at the moment, this part
    is not fitted.
    Basically this are the same as using one small geared motor, but servos are
    cheap, readily available and with a nice servo holder, everyone can replace
    the servo motor. Further the roll extracted from the printer can be
    screwed directly on the servo.

  14. #54
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    Hi to all,
    have someone a idea about automatic nozzle changing between these two
    different nozzles ? I appredicate any help or hint.
    By the way, one commercial and low cost manual smd reel feeder that
    i have used as base for the motorized feeder using rc servos.
    This images comes from the vendor site.
    Regards,
    nisma
    Attached Thumbnails Attached Thumbnails vacuumpenplcc84.jpg   vacuumpen0603.jpg   QX201.JPG   m2-12.jpg  

  15. #55
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    very interesting thread :-)

    I just had a thought: the feeders seem to be a costly and difficult part, but since we seem to be aiming at a speed that's near or just above hand placement, you could use manual feeding. if your x and y are sufficient, then you could manually pull through something like 10 or 20 components and the software could just keep track of where the next part should be, instead of advancing the tape one component after picking a component. You could order the placement so the software switches to the next component after placing up to 20 of the previous component, so it can place 20 of each component unattended, and after that you need to do manual feeding of the used reels. just a thought.
    http://jwstolk.xs4all.nl/mill.htm

  16. #56
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    better yet: add a small pin to the placement head. after picking and placing one component, go back to the reel, insert the pin into the reel, and pull it through one component using the placement head.

    jaap.
    http://jwstolk.xs4all.nl/mill.htm

  17. #57
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    IMHO, RC Servos are not the best solution for reel feeding. True, normal RC servos only rotate ~180 degrees. They have a potentiometer attached to the shaft which provides feedback for the position. You can detach (remove)and "fool" the servo to continually rotate. You have a normal gear reduction motor at this point. However, you have no accurate control how much it rotates. It seems like stepper motor is a better solution

  18. #58
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    Or your could use a rc servo modificated for continuous rotation for advancing
    the feeder. Go to the next office store and select one white taper canceller. There come with with of 8mm and 4.2 or 5mm.
    This parts are perfect for being used as part of cheap feeders in addition to
    modified rc servo.

  19. #59
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    rc servos are cheap and have already the necessary electronic to drive the
    motor. Principally i have used it, because i had some spares laying around.
    The position is checked with a fork type infrared sensor removed from
    the printer, that checks the perforations, that are present every 4mm on
    the reel.
    I only advance in multiple of 4mm. The internal rc potentiometer is repleaced
    with a fixed resistor, as necessary for the continous rotation.

  20. #60
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    That is good info. An IR sensor looks at the holes in the tape and shuts off the motor. The RC servo is also geared for slower speed and higher torgue. This seems like a less complicated way rather then using a stepper motor. I retract my previous comment.

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